Noise Attenuation Methods Applied During Simultaneous Source Deblending and Separation

Abstract

A tangible, non-transitory, machine-readable media, includes instructions configured to cause a processor to determine a residual associated with input seismic data received from a seismic source. The residual is indicative of a difference between expected input seismic data and the input seismic data, and wherein the input seismic data is configured to be combed with an expanded window such that the expanded window comprises data generated by an earlier seismic source excitation and received before a time of a seismic source excitation that generated an input seismic trace corresponding to the input seismic data. The instructions are also configured to cause the processor to determine a deblended output based at least in part on the residual. In addition, the instructions are configured to cause a processor to update the deblended output based at least in part on a result from performing one or more recovery operations configured to recover coherent signals from non-coherent signals of the deblended output. The coherent signals comprise a matching parameter. Further, the instructions are configured to cause a processor to filter the deblended output to remove a portion of the deblended output that is before the time of the seismic source excitation or before a predicted earliest arrival time of a seismic wave travelling from the seismic source to a receiver, to generate an improved deblended output comprising less noise than the deblended output. Still further, the instructions configured to cause a processor to transmit the filtered deblended output for use in generating a seismic image. The seismic image represents hydrocarbons in a subsurface region of Earth or subsurface drilling hazards.

What is claimed is: 
     
         1 . A tangible, non-transitory, machine-readable media, comprising instructions configured to cause a processor to:
 determine a residual associated with input seismic data received from a seismic source, wherein the residual is indicative of a difference between expected input seismic data and the input seismic data, and wherein the input seismic data is configured to be combed with an expanded window such that the expanded window comprises data generated by an earlier seismic source excitation and received before a time of a seismic source excitation that generated an input seismic trace corresponding to the input seismic data;   determine a deblended output based at least in part on the residual;   update the deblended output based at least in part on a result from performing one or more recovery operations configured to recover coherent signals from non-coherent signals of the deblended output, wherein the coherent signals comprise a matching parameter;   filter the deblended output to remove a portion of the deblended output that is before the time of the seismic source excitation or before a predicted earliest arrival time of a seismic wave travelling from the seismic source to a receiver, to generate an improved deblended output comprising less noise than the deblended output; and   transmit the filtered deblended output for use in generating a seismic image, wherein the seismic image represents hydrocarbons in a subsurface region of Earth or subsurface drilling hazards.   
     
     
         2 . The tangible, non-transitory, machine-readable media of  claim 1 , comprising instructions configured to cause, as part of the one or more recovery operations, the processor to:
 perform a separation operation on the deblended output to generate a first subset of signals associated with the coherent signals of the deblended output and a second subset of signals associated with the non-coherent signals of the deblended output;   recover a third subset of signals from the second subset of signals, wherein the third subset of signals comprises the coherent signals of the non-coherent signals of the deblended output, wherein the coherent signals are signals misallocated at least in part on the separation operations that generate the first subset and the second subset of signals; and   update the deblended output based at least in part on the third subset of signals resulting from performing the one or more recovery operations.   
     
     
         3 . The tangible, non-transitory, machine-readable media of  claim 2 , comprising instructions configured to cause, as part of the one or more recovery operations, the processor to:
 perform blending and combing operations on the second subset of signals to generate combed receiver gather data;   subtract the second subset of signals from the combed receiver gather data where coherent signals are leaked into the second subset of signals to generate subtracted receiver gather data; and   after the blending and combing and any subtraction operations, perform an additional separation operation on the combed receiver gather data or the subtracted receiver gather data to generate the third subset of signals and a fourth subset of signals, wherein the third subset of signals comprises recovered coherent signals, and wherein the fourth subset of signals comprises non-coherent signals.   
     
     
         4 . The tangible, non-transitory, machine-readable media of  claim 2 , comprising instructions configured to cause, as part of updating the deblended output, the processor to:
 generate a primary signal estimate based at least in part on the third subset of signals, the second subset of signals and the first subset of signals;   compute the expected input seismic data at least in part by blending the primary signal estimate before blending based on a time of seismic source excitations to generate the signals;   generate the residual based at least in part on a difference between the expected input seismic data and original input data;   perform deblending operations on the residual; and   update the deblended output based on the primary signal estimate and results from the deblending operations.   
     
     
         5 . The tangible, non-transitory, machine-readable media of  claim 4 , comprising instructions configured to cause the processor to:
 additively combine the third subset of signals, the second subset of signals, and the first subset of signals, and the results from the deblending operations on the residual to generate the primary signal estimate.   
     
     
         6 . The tangible, non-transitory, machine-readable media of  claim 1 , wherein the deblended output comprises one or more previously misplaced signals that have been captured and recombined with initially identified coherent signals associated with a primary signal estimate. 
     
     
         7 . The tangible, non-transitory, machine-readable media of  claim 1 , comprising instructions configured to cause the processor to:
 perform the one or more recovery operations after determining the deblended output.   
     
     
         8 . The tangible, non-transitory, machine-readable media of  claim 1 , comprising instructions configured to cause, as part of the one or more recovery operations, the processor to:
 separate the deblended output into the coherent signals and non-coherent signals;   separate the non-coherent signals into additional coherent signals and additional non-coherent signals;   combine the additional coherent signals, and the coherent signals or previously deblended output to update a value of the residual; and   update the deblended output based at least in part on the coherent signals or the previously deblended output, the additional coherent signals, and the updated value of the residual.   
     
     
         9 . A device, comprising:
 a first processor configured to:   determine a residual associated with input seismic data received from a seismic source, wherein the residual is indicative of a difference between expected input seismic data and the input seismic data, wherein the input seismic data is configured to be combed with expanded windows such that the expanded windows comprise data generated by an earlier seismic source excitation and received before a time of a seismic source excitation that generated an input seismic trace corresponding to the input seismic data;   update a value of the residual based at least in part on a separation operation that separates coherent signals from noise signals in an output associated with the residual determined to be remaining energy for separation or a sum of the residual and a primary signal estimate;   extract non-coherent or weak-coherent energy from the coherent signals;   in response to satisfying an end condition, determine a deblended output comprising the coherent signals;   filter the deblended output to remove a portion of the deblended output that is before the time of the seismic source excitation or before a predicted earliest arrival time of a seismic wave travelling from the seismic source to a receiver, to generate a filtered deblended output comprising less noise than the deblended output; and   transmit the filtered deblended output for use in generating a seismic image, wherein the seismic image represents hydrocarbons in a subsurface region of Earth or subsurface drilling hazards.   
     
     
         10 . The device of  claim 9 , wherein the first processor is configured to:
 extract additional coherent signals from the non-coherent or weak-coherent energy; and   in response to satisfying an end condition, determine a deblended output comprising the additional coherent signals.   
     
     
         11 . The device of claim  19 , wherein the first processor, as part of the generating of the additional coherent signals with correct timing, is configured to:
 perform an iterative process that comprises updating, at each iteration, the additional coherent signals to include any further additionally recovered coherent signals.